It's very sad to hear it officially, though I have been expecting it for a while. I have no doubt it's the right decision. I'm glad GC made the call now rather than waiting any longer.
I don't participate in the housing lottery, so I have no dog in that hunt. But it does seem to me to be a huge logistical headache to roll the time slots forward to next year, if it's even possible at all. Given that the company is going to be pretty short on money this year, and still has to make 2021 happen, jumping through a lot of hoops to make sure that everyone who got a good housing slot this year gets one next year has to be pretty close to the bottom of the priority list.
Dittos on 2020 dice - I'd be glad to buy a set.
Finally, what is the best way to support GC and make sure they're still around and able to put on a great con next year? Do they make enough on the branded merchandise to be significant?